A team at City of Hope and Sangamo Therapeutics is genetically modifying patients' blood forming stem cells to functionally cure people with HIV. The team is using a technology called zinc finger nucleases – a kind of molecular scissors – to snip out the target gene that codes for the CCR5 receptor. This receptor is the gateway for the HIV virus into immune cells. The hope is that this treatment will provide a renewable, long-lasting source of HIV resistant immune cells in patients.